Javascript 使用firebase实时数据库云函数增加节点和所有父节点的计数器

我正在使用JSSDK为我的firebase实时数据库（不是firestore）编写云函数。这些函数递增计数器，用于计算每个区域的用户数。我使用的区域是地理区域和嵌套区域（大陆>国家>地区>城市）。将用户插入到给定区域（.onCreate）的用户列表中会触发这些函数。如果用户被插入到某个国家的用户列表中，它将自动添加到父大陆的用户列表中

经过一段时间的修修补补，我只能想出一个“低级”的不可扩展的解决方案（顺便说一句，这是可行的）。这意味着，如果我想将子区域添加到城市，我需要编写附加代码

这是一个问题，因为我希望在将来添加子区域

问：是否有一种方法可以编写一个通用的云函数，该函数增加一个节点及其所有父节点的计数器

我是firebase的新手，非常感谢您的帮助

firebase实时数据库的Json结构 我的云函数用于用户插入-仍然需要为用户删除而编写 我觉得我错过了什么。必须有一种通用的方法来做到这一点

{
  "groups" : {
    "location" : {
      "continents" : {
        "EU" : {
          "countries" : {
            "DE" : {
              "created" : "2019-03-25--20:03:34",
              "flag" : "/flags/de.svg",
              "label" : "Germany",
              "level" : 2,
              "regions" : {
                "BE" : {
                  "cities" : {
                    "Berlin" : {
                      "created" : "2019-03-25--20:03:35",
                      "label" : "Berlin",
                      "level" : 3,
                      "type" : "location",
                      "usercount" : 1,
                      "users" : {
                        "rvDUa5n0oufRFGA9JB7lioom0ac2" : {
                          "created" : "2019-03-25--20:03:55",
                          "label" : "Anonymous"
                        }
                      }
                    }
                  },
                  "created" : "2019-03-25--20:03:35",
                  "label" : "Land Berlin",
                  "level" : 3,
                  "type" : "location",
                  "usercount" : 1,
                  "users" : {
                    "rvDUa5n0oufRFGA9JB7lioom0ac2" : {
                      "created" : "2019-03-25--20:03:52",
                      "label" : "Anonymous"
                    }
                  }
                }
              },
              "type" : "location",
              "usercount" : 1,
              "users" : {
                "rvDUa5n0oufRFGA9JB7lioom0ac2" : {
                  "created" : "2019-03-25--20:03:49",
                  "label" : "Anonymous"
                }
              }
            }
          },
          "created" : "2019-03-25--20:03:33",
          "label" : "Europe",
          "level" : 1,
          "type" : "location",
          "usercount" : 1,
          "users" : {
            "rvDUa5n0oufRFGA9JB7lioom0ac2" : {
              "created" : "2019-03-25--20:03:46",
              "label" : "Anonymous"
            }
          }
        }
      }
    }
  }
}

exports.onUserAddToContinent = functions.database
.ref('/groups/location/continents/{continentID}/users/{userID}')
.onCreate((snapshot, context) => {

const continentId = context.params.continentID
const counterRef = admin.database().ref('/groups/location/continents/' + continentId + '/usercount');

return counterRef.transaction(usercount => {
  return (usercount || 0) + 1
  })
})

exports.onUserAddToCountry = functions.database
.ref('/groups/location/continents/{continentID}/countries/{countryID}/users/{userID}')
.onCreate((snapshot, context) => {

    const continentId = context.params.continentID
    const countryId = context.params.countryID
    const counterRef = admin.database().ref('/groups/location/continents/' + continentId + '/countries/' + countryId + '/usercount');

    return counterRef.transaction(usercount => {
      return (usercount || 0) + 1
      })
})

exports.onUserAddToRegion = functions.database
.ref('/groups/location/continents/{continentID}/countries/{countryID}/regions/{regionID}/users/{userID}')
.onCreate((snapshot, context) => {

    const continentId = context.params.continentID
    const countryId = context.params.countryID
    const regionId = context.params.regionID
    const counterRef = admin.database().ref('/groups/location/continents/' + continentId + '/countries/' + countryId + '/regions/' + regionId +'/usercount');

    return counterRef.transaction(usercount => {
      return (usercount || 0) + 1
      })
})

exports.onUserAddToCity = functions.database
.ref('/groups/location/continents/{continentID}/countries/{countryID}/regions/{regionID}/cities/{cityID}/users/{userID}')
.onCreate((snapshot, context) => {

    const continentId = context.params.continentID
    const countryId = context.params.countryID
    const regionId = context.params.regionID
    const cityId = context.params.cityID
    const counterRef = admin.database().ref('/groups/location/continents/' + continentId + '/countries/' + countryId + '/regions/' + regionId +'/cities/'+ cityId + '/usercount');

    return counterRef.transaction(usercount => {
      return (usercount || 0) + 1
      })
})